Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Wed Oct 07 2020 Valid 101200Z - 151200Z ...DISCUSSION... Medium-range guidance continues to indicate considerable amplification within the westerlies across the mid-latitude Pacific into North America this weekend into early next week. However, there has been considerable spread within the output concerning the short wave developments. This persists and appears to increase, particularly through the early to middle portion of next week in the latest model runs. The pattern still appears likely to include the evolution of large-scale mid-level troughing inland of the Pacific coast, through the Canadian Prairies and U.S. Great Plains by Sunday. This probably will be accompanied by deepening surface troughing to the lee of the Rockies, and embedded surface cyclogenesis Sunday through Sunday night, which may provide the focus for the most appreciable severe weather potential during this period. Where forcing for ascent may be most conducive, across the northern Great Plains, the extent of this potential remains unclear due to uncertain low-level moisture return, in the wake of inland migrating Hurricane Delta. The remnants of Delta might still pose some risk for severe weather east of the lower Mississippi Valley on Saturday, but weak/negligible boundary-layer instability will probably remain a mitigating factor, particularly as low-level wind fields and shear weaken. Otherwise, elsewhere through the remainder of the period, low pattern predictability is a major issue, but guidance, in general, appears to suggest that any severe weather potential may remain relatively minor.
There’s more click here.